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US4293609A Expired / Lapsed US ⏱️ 0.0 years remaining

Flexible absorbent laminates

Assignee: Dow Chemical Co
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Filing: 1980-06-30
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Granted: 1981-10-06
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Expires: 2000-06-30
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Abstract

Abstract Flexible absorbent laminates made from crushed films of lightly crosslinked or water-swellable hydrophilic polymers with layers of wicking substrates are disclosed. The crushed laminates are made by drying the laminates to less than 8% moisture and crushing them preferably between a yieldable roller and an enbossed roller. The crushed laminates have a tissue-like feel at low relative humidities with rapid absorption and are useful to make baby diapers or adult diapers.

Inventors

  • 👤 Robert E. Erickson

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-24 03:18
CPC Classifications
A; A61; A61F; A61F13/00; A61F13/15; A61F13/53; A61F13/15203; A61F13/534; A61F13/537; A61F13/53743; A61F13/539; A61L; A61L15/00; A61L15/16; A61L15/42; A61L15/60; B; B32; B32B; B32B27/00; B32B27/12; A61F13/51; A61F2013/51002; A61F2013/51038; A61F2013/51042; A61F13/514; A61F13/51401; A61F2013/51409; A61F2013/530131; A61F2013/530481; A61F2013/530802; A61F2013/53445; Y; Y10; Y10S; Y10S264/00; Y10S264/47; Y10S428/00; Y10S428/913; Y10T; Y10T428/00; Y10T428/24; Y10T428/24802; Y10T428/24851; Y10T428/249921; Y10T428/249953; Y10T428/249981; Y10T428/31504; Y10T428/31855; Y10T428/3188; Y10T428/31895; Y10T442/00; Y10T442/30; Y10T442/3472; Y10T442/3602; Y10T442/365; Y10T442/60; Y10T442/674

Claims Analysis

Total Claims: 31
Claim 1
Independent Claim 52 words
A flexible hydrophilic absorbent laminate which has a rapid absorption rate and is soft and flexible at low and high relative humidities which comprises (a) a central, substantially discontinuous and crushed film consisting of a water-swellable hydrophilic polymer, and (b) a layer of wicking substrates bonded to both sides of said film.
Claim 2
Dependent Claim 52 words
A flexible hydrophilic absorbent laminate which has a rapid absorption rate and is soft and flexible at low and high relative humidities which comprises (a) a central, substantially discontinuous and crushed film consisting of a water-swellable hydrophilic polymer, and (b) a layer of wicking substrates bonded to both sides of said film.
Claim 3
Dependent Claim 25 words
The laminate of claim 1 wherein the film comprises an aerated film having a density ranging from about 1.1 to 0.3 grams per cubic centimeter.
Claim 4
Dependent Claim 31 words
The laminate of claim 1 wherein the wicking substrates on the top or bottom are selected from the group consisting of woven fabrics, paper tissues, nonwoven fiber mats and polymeric foams.
Claim 5
Dependent Claim 29 words
An absorbent pad which comprises the absorbent laminate of claim 1, one or more layers of wicking substrates, a water impermeable bottom sheet and a water permeable face sheet.
Claim 6
Dependent Claim 23 words
The absorbent pad of claim 4 wherein said water impermeable bottom sheet is polyethylene and said face sheet is a non-woven fiber mat.
Claim 7
Dependent Claim 53 words
A flexible hydrophilic absorbent laminate which has a rapid absorption rate and is soft and flexible at low and high relative humidities which comprises (a) a central, substantially discontinuous and crushed film consisting of a lightly crosslinked carboxylic polyelectrolyte, and (b) a layer of wicking substrates bonded to both sides of said film.
Claim 8
Dependent Claim 53 words
A flexible hydrophilic absorbent laminate which has a rapid absorption rate and is soft and flexible at low and high relative humidities which comprises (a) a central, substantially discontinuous and crushed film consisting of a lightly crosslinked carboxylic polyelectrolyte, and (b) a layer of wicking substrates bonded to both sides of said film.
Claim 9
Dependent Claim 25 words
The laminate of claim 6 wherein the film comprises an aerated film having a density ranging from about 1.1 to 0.3 grams per cubic centimeter.
Claim 10
Dependent Claim 31 words
The laminate of claim 6 wherein the wicking substrates on the top or bottom are selected from the group consisting of woven fabrics, paper tissues, non-woven fibers mats and polymeric foams.
Claim 11
Dependent Claim 29 words
An absorbent pad which comprises the absorbent laminate of claim 6, one or more layers of wicking substrates, a water impermeable bottom sheet and a water permeable face sheet.
Claim 12
Dependent Claim 23 words
The absorbent pad of claim 9 wherein said water impermeable bottom sheet is polyethylene and said face sheet is a non-woven fiber mat.
Claim 13
Dependent Claim 97 words
A hydrophilic absorbent laminate which has a rapid absorption rate and is soft and flexible at low and high relative humidities which comprises (a) a central, substantially discontinuous, cracked and aerated film having a density from about 1.1 to 0.3 grams per cubic centimeter and consisting of a lightly crosslinked carboxylic polyelectrolyte, and (b) a layer of wicking substrates bonded to both sides of said film wherein said substrates on the top or bottom are the same or different and are selected from the group consisting of woven fabrics, paper tissues, non-woven fiber mats and polymeric foams.
Claim 14
Dependent Claim 97 words
A hydrophilic absorbent laminate which has a rapid absorption rate and is soft and flexible at low and high relative humidities which comprises (a) a central, substantially discontinuous, cracked and aerated film having a density from about 1.1 to 0.3 grams per cubic centimeter and consisting of a lightly crosslinked carboxylic polyelectrolyte, and (b) a layer of wicking substrates bonded to both sides of said film wherein said substrates on the top or bottom are the same or different and are selected from the group consisting of woven fabrics, paper tissues, non-woven fiber mats and polymeric foams.
Claim 15
Dependent Claim 11 words
The laminate of claim 11 wherein said substrates are woven fabrics.
Claim 16
Dependent Claim 12 words
The laminate of claim 11 wherein said substrates are non-woven fiber mats.
Claim 17
Dependent Claim 11 words
The laminate of claim 11 wherein said substrates are paper tissues.
Claim 18
Dependent Claim 11 words
The laminate of claim 11 wherein said substrates are polymeric foams.
Claim 19
Dependent Claim 12 words
The laminate of claim 15 wherein said polymeric foams are polyurethane foams.
Claim 20
Dependent Claim 69 words
A process for making the flexible laminate of claim 1 which comprises (a) reducing the moisture content of a laminate of a water-swellable hydrophilic polymer film with wicking substrates to less than 8% by weight by passing said laminate through a drying zone, and (b) passing said dried laminate through a crushing zone wherein said film breaks into a plurality of pieces which remain essentially laminated to said substrates.
Claim 21
Dependent Claim 101 words
A process for making the flexible laminate of claim 1 which comprises (a) reducing the moisture content of a laminate of a water-swellable hydrophilic polymer film with wicking substrates to less than 8% by weight by passing said laminate through a drying zone, and (b) passing said laminate through a cracking zone having a first roller with a yieldable surface coacting with a second roller with a predetermined patterned surface whereby said laminate is squeezed between said rollers with sufficient pressure to crack said film substantially completely into a plurality of pieces with a minimum amount of tearing of said substrates.
Claim 22
Dependent Claim 18 words
The process of claim 18 wherein said laminate moisture content is in the range from 1 to 6%.
Claim 23
Dependent Claim 30 words
The process as set forth in claim 18 wherein said first roller has an elastomeric surface wherein the elastomer has a Durometer A hardness from about 40 to about 100.
Claim 24
Dependent Claim 18 words
The process as set forth in claim 20 wherein said first roller is made from a synthetic rubber.
Claim 25
Dependent Claim 21 words
The process as set forth in claim 18 wherein said second roller is made from steel with an engraved surface pattern.
Claim 26
Dependent Claim 69 words
A process for making the flexible laminate of claim 6 which comprises (a) reducing the moisture content of a laminate of a lightly crosslinked polyelectrolyte fiim with wicking substrates to less than 8% by weight by passing said laminate through a drying zone, and (b) passing said dried laminate through a crushing zone wherein said film breaks into a plurality of pieces which remain essentially laminated to said substrates.
Claim 27
Dependent Claim 101 words
A process for making the flexible laminate of claim 6 which comprises (a) reducing the moisture content of a laminate of a lightly crosslinked polyelectrolyte film with wicking substrates to less than 8% by weight by passing said laminate through a drying zone, and (b) passing said laminate through a cracking zone having a first roller with a yieldable surface coacting with a second roller with a predetermined patterned surface whereby said laminate is squeezed between said rollers with sufficient pressure to crack said film substantially completely into a plurality of pieces with a minimum amount of tearing of said substrates.
Claim 28
Dependent Claim 18 words
The process of claim 24 wherein said laminate moisture content is in the range from 1 to 6%.
Claim 29
Dependent Claim 30 words
The process as set forth in claim 24 wherein said first roller has an elastomeric surface wherein the elastomer has a Durometer A hardness from about 40 to about 100.
Claim 30
Dependent Claim 18 words
The process as set forth in claim 26 wherein said first roller is made from a synthetic rubber.
Claim 31
Dependent Claim 21 words
The process as set forth in claim 24 wherein said second roller is made from steel with an engraved surface pattern.

References Cited (Backward Citations)

US3670731A Cited
US3669822A Cited
US3888256A Cited
US3890974A Cited
US4076673A Cited
US4117184A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1984-10-05 1985-04-06 1985-10-06 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1988-10-05 1989-04-06 1989-10-06 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1992-10-05 1993-04-06 1993-10-06 $7700.00 Window Closed / Lapsed

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